ASTM A738 Carbon Steel Tube,Pipe, Grade B

ASTM A738 Carbon Steel Tube, Grade B Product Information -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel Tube, Grade B Synonyms -:- For detailed product information, please contact sales. -:

ASTM A738 Carbon Steel, Grade B Product Information -:- For detailed product information, please contact sales. -: # **Product Introduction: ASTM A738 Grade B Carbon-Manganese-Silicon Steel for Low-Temperature Pressure Vessels** **ASTM A738 Grade B** is a **heat-treated carbon-manganese-silicon steel plate** engineered for **welded pressure vessels requiring enhanced strength and guaranteed notch toughness at low temperatures**. As a higher-strength grade within the A738 specification, it provides a **minimum yield strength of 60 ksi (415 MPa)** with mandatory impact toughness testing. This grade is supplied exclusively in the **normalized and tempered or quenched and tempered condition**, ensuring a refined, uniform microstructure capable of withstanding the combined stresses of pressure loading and low-temperature operation. The steel's balanced chemistry and controlled heat treatment make it a reliable choice for critical containment applications where brittle fracture prevention is paramount. --- ## **International Standard & Key Specifications** * **Primary Standard:** **ASTM A738/A738M** - Standard Specification for Pressure Vessel Plates, Heat-Treated, Carbon-Manganese-Silicon Steel, for Moderate and Lower Temperature Service. * **Key Characteristic:** **Mandatory heat treatment** distinguishes this specification from conventional carbon steel plates, ensuring consistent through-thickness properties. * **ASME Code Equivalent:** **SA-738/SA-738M** in ASME Boiler and Pressure Vessel Code, Section II, Part A. Required for ASME-stamped pressure equipment. * **Governing Standard:** **ASTM A20/A20M** - Standard Specification for General Requirements for Steel Plates for Pressure Vessels. * **Impact Test Mandate:** All plates must undergo **Charpy V-notch impact testing** at specified temperatures, with defined minimum energy absorption requirements. --- ## **Chemical Composition (Weight %, max unless range is specified)** The composition is optimized to achieve higher strength while maintaining good weldability and response to heat treatment. | Element | Composition (%) | Role in Performance | | :--- | :--- | :--- | | **Carbon (C)** | 0.27 max | Higher than Grade A to enhance strength; controlled to maintain weldability. | | **Manganese (Mn)** | 1.00 - 1.60 | Primary strengthener; increased range improves hardenability for higher strength. | | **Phosphorus (P)** | 0.035 max | Impurity, minimized for optimal notch toughness. | | **Sulfur (S)** | 0.040 max | Impurity, controlled to ensure good weldability and ductility. | | **Silicon (Si)** | 0.15 - 0.40 | Deoxidizer and solid solution strengthener. | | **Nickel (Ni)** | **0.40 max (optional)** | May be added by agreement to significantly enhance low-temperature toughness. | | **Copper (Cu)** | 0.35 max | Residual element, typically present. | | **Vanadium (V)** | 0.05 max | May be present for grain refinement. | | **Carbon Equivalent (CE)** | Typically ≤ 0.48 | Calculated to ensure adequate weldability despite higher carbon content. | **Key Distinction:** Higher carbon and manganese limits compared to Grade A enable the increased strength level while the optional nickel addition can be utilized for demanding low-temperature applications. --- ## **Typical Physical & Mechanical Properties** Properties are guaranteed after the specified heat treatment (normalized and tempered or quenched and tempered). | Property | Value / Description | | :--- | :--- | | **Tensile Strength** | 550 - 690 MPa (80,000 - 100,000 psi) | | **Yield Strength (min)** | **415 MPa (60,000 psi)** | | **Elongation in 2-in (50 mm) (min)** | 19% | | **Modulus of Elasticity** | ~200 GPa (29 x 10⁶ psi) | | **Density** | ~7.85 g/cm³ (0.284 lb/in³) | | **Charpy V-Notch Impact Toughness** | **Test Temperature:** **-50°F (-45°C)**. **Minimum Avg. for 3 Specimens:** **20 ft·lbf (27 J)**. **Minimum Single Value:** 15 ft·lbf (20 J). | | **Brinell Hardness (typical)** | 190 - 240 HBW | | **Design Advantage:** Approximately 20% higher allowable stress values compared to Grade A in ASME Code applications. | --- ## **Product Applications** ASTM A738 Grade B is specified for pressure vessels operating under conditions where both higher design pressures and low-temperature toughness are required, enabling more efficient, thinner-walled designs. **Primary Industries and Equipment:** 1. **Gas Processing & Petrochemical:** * **Low-Temperature Separators** and **Scrubbers** in natural gas processing. * **Ammonia and Urea Process Vessels**. * **LPG Storage Tanks** with higher design pressures. 2. **Power Generation:** * **High-Pressure Feedwater Heaters**. * **Moisture Separator Reheaters (MSRs)**. * **Hydrogen Cooler Shells** in turbine systems. 3. **Cryogenic & Refrigeration:** * **Liquid Carbon Dioxide Storage Vessels**. * **Industrial Refrigeration System Pressure Vessels**. * **Process Equipment** for chemical plants with low-temperature cycles. 4. **Industrial Manufacturing:** * **High-Pressure Accumulators**. * **Custom Fabricated Pressure Vessels** for specialized processes. * **Heat Exchangers** for services combining pressure and low temperature. --- ## **Advantages and Critical Fabrication Considerations** * **Advantages:** * **Higher Strength with Guaranteed Toughness:** 60 ksi yield strength with mandatory impact testing provides reliable performance envelope. * **Material Efficiency:** Higher strength allows for thinner wall sections, reducing weight and material costs. * **Heat Treatment Consistency:** Normalized and tempered or quenched and tempered condition ensures uniform properties. * **Code Compliance:** Fully compliant with ASME Section VIII, Division 1 and 2 requirements for pressure vessels. * **Critical Fabrication & Welding Considerations:** * **Carbon Equivalent Management:** Higher CE requires careful welding procedure development. **Low-hydrogen processes are mandatory.** * **Preheat Requirements:** More stringent than Grade A, especially for thicker sections. Typical range: 200-300°F (95-150°C). * **Post-Weld Heat Treatment (PWHT):** Generally required for pressure vessel fabrication. PWHT temperature must be controlled to avoid overtempering the base metal. * **Welding Consumable Selection:** Filler metals should match or slightly undermatch the base metal strength to ensure weld metal toughness. * **Impact Test Verification:** Welding Procedure Specifications (WPS) should be qualified with impact testing of weld metal and HAZ when service temperatures are low. * **Thermal Cutting Precautions:** Preheating before flame cutting is recommended to prevent hydrogen cracking. * **Thickness Limitations:** As thickness increases, achieving both strength and toughness becomes more challenging; properties should be verified for specific thickness ranges. **In summary, ASTM A738 Grade B is a heat-treated carbon steel plate offering a 60 ksi minimum yield strength with guaranteed impact toughness at -50°F. Its enhanced strength-to-weight ratio makes it particularly suitable for pressure vessel designs where weight reduction and higher pressure capabilities are important, while its mandatory heat treatment and impact testing ensure reliable performance in low-temperature service. This grade represents an optimal balance between performance and cost for demanding pressure vessel applications across multiple industries.** -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel, Grade B Specification Dimensions Size： Diameter 20-1000 mm Length <4535 mm Size:We can customized as required Standard： Per your request or drawing We can customized as required Properties（Theoretical） Chemical Composition -:- For detailed product information, please contact sales. -: ASTM A738 Carbon Steel, Grade B Properties -:- For detailed product information, please contact sales. -:

Applications of ASTM A738 Carbon Steel Tube, Grade B -:- For detailed product information, please contact sales. -: Chemical Identifiers ASTM A738 Carbon Steel Tube, Grade B -:- For detailed product information, please contact sales. -:

Packing of ASTM A738 Carbon Steel Tube, Grade B -:- For detailed product information, please contact sales. -: Standard Packing: -:- For detailed product information, please contact sales. -: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and Steel Tube drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 1006 gallon liquid totes Special package is available on request. E FORUs’ is carefully handled to minimize damage during storage and transportation and to preserve the quality of our products in their original condition